The present invention relates to a tube filter assembly of the kind comprising a housing having a perforated wall defining a dirty gas chamber with a raw gas inlet and a clean gas chamber with a clean gas outlet, said dirty gas chamber and containing filter tubes which are attached to the perforated wall in a sealed fashion and are arranged to be periodically cleaned by counter-current scavenging from the clean gas side, said filter tubes being arranged in the dust removal space, covering the holes in the perforated wall at their open ends, and being provided with an internal spacer member.
In prior art filter tube assemblies it is known that the rim of the open end of the filter tube is to be attached in a special manner, e.g. by clamping the rim of the tube firmly against the perforated wall or partition by means of a screw-on clamping flange, thus making it necessary for a considerable amount of time and labor to be expended when fitting the filter tubes and exchanging defective ones, apart from the fact that in time the seal becomes less tight because the rim of the openings in the tubes, which is generally toroidal, contracts as a result of drying. In general, it is also necessary with such tube filters to compensate for stretching of the material of the tubes by means of tensioning devices.
It is an object of the invention to connect the circumferential rim at the open end of the filter tubes to the perforated wall dividing the filter housing in an air-tight fashion on the clean gas side without using screws and to make it possible for each filter element to be inserted into the dirty gas chamber from the clean gas side through a hole in the perforated wall while using a spacer member of the cheapest and simplest design.
It is another object of the invention to make the filter tubes and their spacer members in such a way that no creases are formed in the filter tubes but no active filter surface is lost and without the need for tensioning devices.